Patent Document 1 discloses the technology as a sunshade device. In the motor-driven sunshade device of Patent Document 1, a lower edge of a screen having a shape corresponding to a rear window of a vehicle is secured to a windup roller, and an upper edge thereof is secured to a horizontal frame, whereby the rear window is shaded by extending the screen upward or downward with vertical frame arms therebetween. The windup roller is constantly biased in the direction in which the screen is wound up by an incorporated coil spring. More specifically, as shown in FIG. 3 of Patent Document 1, the motor-driven sunshade device includes vertical arms each including a mounting part, a pivot part and an arm part. The vertical arm is configured so as to rotate upward and downward along a plane parallel to the window with a pivot shaft provided to a back surface of a proximal end of the mounting part in a projecting manner to be directly connected to a motor. Further, the vertical arm is mounted to the horizontal frame via a sliding member such that an upper end of the arm part slides left and right. Then, the sliding member slides left and right along the horizontal frame along with the pivot of the vertical arm, whereby the screen is extended upward and downward.